Silo doorstep and latch device



Sept. 2, 1958 W. D. 'RICH ETAL SILO DOORSTEP AND LATCH DEVICE Fil'ed' May 16, 1957 INVENTOR5 Wdazm fl 2500/2, syfiollze JIM/T672015,

or more steps that serve as foot and hand holds.

United States atent Ofiice Patented Sept. 2, 1958 siLo noonsrnr AND LATCH DEVICE Application May 16, 1957, Serial No. 659,572

4 Claims. (Cl. 20-68) Our invention relates to a silo doorstep and latch device, and more particularly, to silo door hardware that latches the door in place in the silo doorframe and provides steps or foot and hand holds that permit one to climb from one silo door to another up and down the silo.

Silos are conventionally provided with a continuous doorway extending vertically substantially from the top to the bottom of the silo. The doorway is closed by a plurality of doors mounted in doorframes positioned one above the other, the doors being removed or added one by one as the silo is emptied or filled with grain or the like.

Silo doors are conventionally designed to open from the inside of the slio, and are provided on their outwardly facing sides with latch devices that hold them in the doorway when the level of the grain or the like is below the level of the door. The latching devices conventionally engage the outer surfaces of the doorframes, and to remove the door, one releases the latching device of the door, pushes the door inwardly, and then tilts it as required to withdraw the door from the doorway. On replacement of the door, the operation is reversed.

Latching devices conventionally employed on silo doors are ordinarily so arranged that they may provide one The latching devices of all the slio doors thus form a ladder that permits one to climb to the top of the silo.

Conventional silo doors are so designed that their outer surfaces are spaced inwardly of the outer surface of the doorframes. This means that the latching devices must be so designed, and secured to the doors in such a manner, that the latching elements will engage theouter surfaces of the doorframes or other silo structures. In accordance with conventional designs, much of the structure forming the latching devices is spaced from the door, which results in considerable twist being applied thereto when supporting the climber. Moreover, conventional latching devices do not include sufiicient bracing structures, and thus it frequently happens that the weight of the climber tends to tear them away from the door.

A principal object of the invention is to provide a doorstep and latching device for silo doors which is secured flush against the door and provides adequate bracing for the step forming members.

A further object of our invention is to provide an improved latch device for silo doors. I

Another object of the invention is to provide a silo doorstep and latching device which is composed of few and simple parts, is economical of manufacture, and is highly efiicient and safe in use.

Other objects, uses, and advantages will be obvious or become apparent upon a consideration of the following detailed description and the application drawing.

In the drawing:

Figure 1 is a diagrammatic elevational view illustrating a silo to which my invention has been applied;

Figure 2 is an enlarged elevational View of a silo door and doorframe of the type shown in Figure 1, illustrating a preferred embodiment of the invention;

Figure 3 is a cross-sectional view along line 3-3 of Figure 2;

Figure 4 is an enlarged fragmental view of one of the latching pawls or arms shown in Figure 2;

Figure 5 is a diagrammatic cross-sectional view approximately along line 55 of Figure 4, partially in plan; and

Figure 6 is a view similar to that of Figure 4 illustrating the supplemental latching position of the latching pawl or arm.

Reference numeral 10 of Figure 1 generally indicates a silo of the type to which our invention may be applied. Silo 10 may be formed from concrete staves and encircled by spaced hoops 12 in accordance with the disclosure of Patent No. 2,120,838 granted to Rollie A. Lawrence. The silo 10 is conventionally provided with a vertically extending doorway 14 in which a plurality of reinforced concrete doorframes 16 are mounted. Each doorframe 16 receives a treated wood door 18 of conventional design, and the respective doors 18 in accordance with my invention are provided with doorstep and latching devices 20. I

Referring to Figure 2, devices 20 each comprise a pair of vertically disposed, spaced apart angle bars 22 secured to the door 18 so that flanges 24 thereof are flush against the outer surface of the door andprojectaway from each other, and flanges 26 project outwardly of the door. The flange 24 of each bar 22 receives a bolt 28 a't-approximately its mid-point. Bolts 28 each carry washers 30 and 32 as well as a spacing sleeve 34 which in turn carries a substantially Z-shaped latching pawl or arm 36. I The segment 38 of each pawl or arm 36 is formed with a perforation sufficiently large to loosely receive a sleeve 34, while segment 40 of each separates a segment 42 from a segment 38 sufficiently so that segments 42 engage the outer surface of the doorframe as indicated in Figure 3 when the arms are in a horizontal position.

A nut 44 received on each bolt 28 sectu'esthe respective bars 22, washers 30 and 32, sleeves 34, and pawls or arms 36 to the door, though sleeves '34 being longer in length than the thickness of the segments 38, arms 36 will be mounted for pivotal movement on the respective bolts 28. 1

In the illustrated embodiment, as indicated in Figures 4 and 6, the segment 38 of each arm 36 at its inner end includes an extension which is trimmed at one corner thereof asat 50 to provide an abutment surface 52 and a supplementary abutting corner 54. The bolt 28 of each angle bar 22 is preferably so positioned with respect to the flange 26 thereof that the pivotal movement of the pawl or arm 36 is limited to that between a substantially vertical position and a substantially horizontal outwardly extending position (see Figure 2). In the horizontal position, the abutting surface 52 of the respective arms 36 is-in contact with an adjacent flange 26. I

The respective corners 54 are preferably proportioned with respect to the axes about which arms 36 pivot so that as an arm 36 moves downwardly about its bolt 28 to the horizontal position, its corner 54 will contactv the adjacent flange 26 in the manner indicated in Figure 6. The respective corners 54 thus serve as supplemental stops which hold the respective latching arms 36 in the intermediate dotted line positions'indicated in Figure 2 until the person handling the door moves the latching 3 pawl or arm 36 to free corner 54 from the flange 26, whereupon the pawl or arm will-drop to the horizontal position. It will be found that this can be done when most resilient metals are employed for making members 26 and 36.

However, the cooperation above described. between the latching arms and flanges '26 -maybe eliminated so long as means are provided to insure that the arms remain infirm engagement with the doorframes 16 in per forming their latching functions,

A U-shapedmember 60 is secured between the lower ends of bars 22 as by being welded to the flanges 26 thereof, and an upper U-shaped member 62 is secured to the bars in like manner. The members 60 and 62 are identical and form the stepsof the device, and their vertical'spacing ispreferably consistent with the spacing betweensteps of adjacent doors; this may =be accomplished by spacing members 60 and 62 along the lengths of bars '22 as required to provide the desired spacing. The framing elements forming devices 20, namely, bars 22 and members 60 and 62, are preferably preassembled with members 66 and 62 being welded or otherwise affixed toflanges'24. I v

A device 20 may be secured to'a -door 18 solely by the bolts 28 that pivotally mount latching pawls or arms 36 to bars 24. If desired, however, additional bolts or other securing means may be applied to the flanges 24 of members 22.

The latching arms or pawls 36 are both shown in latching position (the full lineillustration thereof) in Figure 2. When it is required to remove a door 18, one merely has to pivot the arms or pawls 36 to the dotted line vertical position, push the door inwardly of the doorframe, and then tilt same as is necessary to remove the door from the silo. The supplemental stops formed by corners 54 prevent thearms or pawls 36 from moving downwardly beyond the dotted line angled positions indicated in'Figure 2, whichinsures that they will not interfere withfthe removal of the door from the doorframe. I

When it is desired to-replace the door, one pushes the latching arms or pawls 36 to the dotted line vertical position and then tilts the door as required to insert same into the silo through --the oper 1ing;.in the doorframe and then place same inv position in thedoorframe. 1

Again, the corners 54 ,insurethat the arms or pawls 36 do not move downwardly beyond the dotted line angled position of Figure 2, which insures that they. will not interfere with the replacement of the door in the doorframe. Latching arms or pawls 3.6 are then pivoted to their illustrated horizontal positions to bring their segments 42 into contact with the outer surface of the doorframe in the manner indicated in Figure 3.

It thus will be seen that we have provided a silo doorstep and latching device which is-composedgof the simplest of elements, and yetwhich is secured to the silo door in a manner that will best resist forces that are imposed upon it. The members22, 60,-and 62 form a substantially quadrilateral framework that in effect is secured flush to the outer surface of the door, and the relatively long length of the members 22 above and be,- low bolts 28 means that the device 2-0 is adequately braced against any twisting forces that are imposed upon it by a climber applying weight to the -members 60 and 62. The angled segments 40 of latching-arms or pawls 36 permit the devices-20 to latch the door in place in spite of the fact that the members 22 are secured flush against the outer surface 30f the'door. The foregoing description and the 'drawingmregiven merely to explain and illustrate our invention-and the invention is not to be limited thereto exceptffin'sofar as the appended-claims are so limited, since ;--those skilled in the art who have our'disclosurej beforejthem will be able to make modifications-and variations therein without departing from the scope of the invention.

We claim:

1. A silo doorstep and latch-device comprising a pair of spaced vertically disposed angle bars positioned against the outer surface of the door with adjacent flanges extending normally of the door and opposed flanges flush with the door, upper and lower substantially U-shaped step members fixed between said adjacent flanges, with the legs of said step members being substantially perpendicular to the door, said bars and said step members forming a generally quadrilateral framework, a bolt positioned adjacent the midpoint of each bar securing said framework flush against the silo door, said bolts each pivotally mounting a latch arm, stop means limiting the pivotal movements of the respective arms to that between a substantially vertical upwardly extending position and a substantially horizontal position wherein the arms extend outwardly of the framework sufliciently to latch the silo door against removal, and supplemental stop means for each of said arms, said supplemental stop means stopping "the, downward pivotal movement of said arms at a position intermediatethe said vertical and horizontal positions, said supplemental stop means being releasable to permit said arms to move to said horizontal positions.

2. A silo door step and latch device comprising a pair of spaced vertically disposed angle bars positioned against the outer surface of-thedoor with adjacent flanges extending no'rmallyof the door and opposed flanges flush with the door and extending away from each other along the plane of the door, upper and lower substantially U- shaped stepmembers fixed between said adjacent flanges, with the legs of said step members being substantially perpendicular to the door, said bars and said step mem bers formingagenerally quadrilateral framework that is adapted to bepositioned flush against the silo door, a bolt positioned adjacent the midpoint of each bar securing said framework flush against the silo "door, ;said bolts each pivotally mounting a latch arm, and stop means for each of'said latch arms for limiting the pivotal movements of the respective arms to that'between a substantially vertical upwardly extending position and substantially horizontal position wherein the arms extend outwardly of the door sufiiciently to latch the silo door against removal, said flanges of said. bars comprising said stop means, and said arms each including an extensionpro portion'ed to engage said flanges, respectively, to hold said arms in said substantially horizontal position, said latch armsengaging said flanges respectively to position same in said substantially vertical: positions.

3. A silo doorstep and latch device comprising a generally quadrilateral framework adapted to be cured flush to the silo door, said framework including a pair of spaced steps positioned adjacent the top and bottom thereof, a latching arm pivotally secured adjacent the midpoint of each side thereof, and stop means for each of said latching arms for limiting the pivotal movements of the respective arms to that between a substantially vertical upwardly extending position and a substantially horizontal position wherein the respective arms extend outwardly of the framework sufficiently to latch the silo door against removal, said stop means being carried by said framework and respectively interposed in the paths of movement of the respective latching arms.

4. In a silo door adapted to be received in a doorframc of a silo, a doorstep and latch device therefor'comprising a pair of spaced vertically disposed bars,--upper and lower step members fixed between said bars in spaced apart relation, saidbars and said step members forming a generally quadrilateral framework that is adapted to be positioned flush against the silo door, a latch arm pivotally mounted adjacent the midpoint of each bar, stop means for each of said latch arms for limiting the pivotal movements of the respective arms to that between a substantially: vertical upwardly extending position and a sub stantially horizontal position wherem the respective arms extend outwardly of the framework sufliciently to latch the silo door against removal, said stop means being carried by said bars respectively and interposed in the path of pivotal movements of the respective latch arms, and means for securing said framework flush against the silo door.

References Cited in the file of this patent UNITED STATES PATENTS 1,322,690 Griswold Nov. 25, 1919 1,902,949 Condon Mar. 28, 1933 2,187,286 Tillman Aug. 10, 1938 2,634,146 Johnson Apr. 7, 1953 

